• A female employee at a home-improvement store is assigned to a cash register, despite previous experience in a lumberyard that would qualify her for a sales-floor job (the springboard for promotions).

If you said the 1960s or '70s, try again. All three incidents took place in the past 10 years. The first two resulted in payments to the affected women and agreements by the companies to try to eliminate discriminatory practices. The third stems from a lawsuit against Wal-Mart now working its way through the courts.

More than 100 women have submitted statements to the US District Court in San Francisco, charging discrimination in the form of unequal pay and barriers to promotion. If their request to classify this as a class-action suit is granted, the class would include 1.6 million women who have worked at Wal-Mart since 1998.

That would make it the largest employment class-action suit in United States history - one that would have "seismic impact," says Adam Forman, an attorney with Testa, Hurwitz, & Thibeault in Boston, which is not involved in the case.

The potential for a full battle in court ora gargantuan settlement has lawyers and employers alike watching from the edges of their seats. And the case could bring sex discrimination to the public's attention in a way not seen since Anita Hill's accusations against Clarence Thomas in 1991 forced a national conversation on sexual harassment.

However the case is resolved, it raises the specter of gender stereotypes that many assume had disappeared long ago.

"We don't hear very much anymore of people willing to say women should be home with their children, or a man should make more because he's supporting [a family] ... but the notion of women not being interested [in certain jobs] is still quite pervasive," says Joyce K. Fletcher, a professor at Boston's Simmons School of Management and its Center for Gender in Organizations.

Those more subtle stereotypes "are so embedded in the culture that it just seems like common sense, it doesn't seem like bias," she says.

No one denies women's overall advancement in the past few decades. In 1966, women constituted 31 percent of employees but only 9.3 percent of officials and managers at companies with more than 100 workers, according to the Equal Employment Opportunity Commission (EEOC). By 2002, women accounted for 48 percent of employees and 36.4 percent of officials and managers.

But sex discrimination remains the second most common type of complaint to the EEOC (after race) - with about 25,000 filed each year, the vast majority from women.

One reason sex discrimination persists is that class-action lawsuits often end in monetary settlements, without much monitoring of the improvements a company is supposed to make afterward, says Michael Selmi, a law professor at George Washington University and author of a recent Texas Law Review article on key discrimination suits.

But firms can make significant changes if their leaders see value in eliminating exclusionary practices that are bad for business, he says. "There have to be rewards for diversifying the workforce, for having more women in management.... There has to be a commitment that it's the right thing to do."

'Fair shake' sought

To the women suing Wal-Mart, promotions there have been anything but fair. Christine Kwapnoski had been working at Sam's Club (owned by Wal-Mart) for 15 years when she became one of the named plaintiffs in June 2001. "There have been a ton of guys promoted over me, time and time again," she says in a phone interview from her home in Concord, Calif. When she asked her manager why men with significantly less experience were earning higher pay and promotions, she says he told her that the men had families to support. It's a story echoed by other plaintiffs, and it especially stung Ms. Kwapnoski, who pays child support for a 14-year-old and a 10-year-old.

Within weeks of the lawsuit being filed, Wal-Mart promoted Kwapnoski, and this year she entered the management training program. But she hopes the lawsuit will help other women, too. "I don't want them to just promote women out of fear," she says. "We just want a fair shake. I've seen a lot of women managers who were really good who got run out of town ... and that's what I'd like to stop."

Women made up about 65 percent of the hourly staff at Wal-Mart, but only 33 percent of salaried management - and at each rung up the ladder, women's representation drops, according to a report submitted by the women's attorneys.

Wal-Mart offers a different analysis. "Wal-Mart does not tolerate discrimination against women or anyone else," says Sarah Clark, a company spokesman, in an e-mailed statement. "When you look at Wal-Mart's growth and the fact that we promote women at the same rate they apply for jobs - or better - you can see that Wal-Mart provides more opportunities for women than any other employer in the country."

Ms. Clark would not comment specifically on the lawsuit. But in court, Wal-Mart presented data to show that any alleged problems were related to individual stores and did not represent a companywide pattern.

Traditional roles

Some argue that the label "discrimination" can be slapped onto situations too quickly. "Sometimes women make less [money] not because of discrimination, but because they've taken time off to be with their kids.... Or a woman might decide she needs flex time and that might keep her out of a management position," says Charlotte Hays, senior editor at the Independent Women's Forum in Washington, D.C.

If companies want to retain more women and see them advance to top jobs, Ms. Fletcher says, they may need to examine how those jobs are defined. "Is it because it's the best way for getting that work done, or is it defined in the way that men have always done it, because of their particular life situation in our society?"

In 1973, Sears was charged with not hiring women and men on an equal basis for sales-commission jobs, which yielded higher pay. Sears argued that most women weren't interested in such jobs. With only statistics to go on and no "smoking gun" testimony from women, the case was finally resolved in favor of Sears in 1988.

A few years later, anecdotes did accompany statistics in a class-action suit against Home Depot's western division. About 70 percent of the sales-floor jobs were held by men, while 70 percent of cashiers were women - including the one who had worked in a lumberyard. While not admitting discrimination, Home Depot settled that and several smaller claims for $104 million in 1997. It also made some changes. Instead of managers steering people informally into jobs, openings are now posted companywide.

Company leaders should know by now to examine their policies and make sure there isn't room for decisions based on stereotypes, says Nancy Dowd, a law professor at the University of Florida in Gainesville. "Anytime there's a word-of-mouth, informal way that promotions occur, that's a huge red flag you've got to deal with.... It might be OK ... but you have to make sure the mentoring and opportunity structures are truly open and nondiscriminatory."

[Editor's note: The original version of this story included a chart of top five sex-discrimination class-action settlements.]